As reported to the American Chemical Society (ACS), University of Minnesota researchers have discovered a previously unrecognized way that degradation can occur in silicone-urethane plastics often used in medical devices. Their study, published in ACS' journal Macromolecules, could have implications for device manufacturers considering the use of these plastics in the design of some implantable devices, including cardiac defibrillation leads.
They said that while these materials have been extensively studied for failure due to interaction with oxygen, no published study examined their interaction with water as a potential failure mechanism.
Their laboratory tests, including accelerated aging of the materials under conditions that simulated being inside a human body, found indications that the material begins to break down within 3 to 6 years, which could have major implications for implanted devices, such as pacemakers and defibrillators.
